The present invention relates to a circuit breaking apparatus for electrically breaking an interval between a power source portion and a load portion.
In the case of, for example, an electric automobile, a capacity of a power source which is a battery, is larger than that of an ordinary gasoline engine vehicle or the like. Therefore, when an electric system or the like thereof is subjected to maintenance, a power source circuit is opened (turned off) by a circuit breaking apparatus to thereby ensure safety of operation. There is a related circuit breaking apparatus of this kind as shown by FIG. 26.
As shown by FIG. 26, a circuit breaking apparatus 200 is provided with a main relay 202 and a sub relay 203 respectively controlled to open and close by a control unit 201 and both of the main relay 202 and the sub relay 203 are provided with power source side terminals 205 and 206 connected to a power source portion 204 and load side terminals 208 and 209 connected to a load portion 207. The load side terminal 209 of the sub relay 203 is connected to the load portion 207 by way of a resistor 210.
According to the above-described constitution, when the main relay 202 and the sub relay 203 are disposed at opened positions and a power source circuit is closed, there is carried out a control of closing firstly the sub relay 203 and closing the main relay 202 after elapse of a predetermined time period by the control unit 201. The power source portion 204 and the load portion 207 are connected via the resistor 210 by firstly closing the sub relay 203 and therefore, a capacitor or the like of the load portion 207 is charged by small current and after charging has been finished, the main relay 202 is closed to thereby connect the power source portion 204 and the load portion 207 directly without interposing a resistor.
That is, in the case in which the load portion 207 is provided with a capacitor or the like, when the sub relay 203 is not provided and only the main relay 202 is provided and the power source portion 204 and the load portion 207 are abruptly connected directly without interposing a resistor, in bringing the power source side terminal 205 and the load side terminal 208 into contact with each other, large current flows to the capacitor or the like via the terminals and therefore, arc discharge is generated between the terminals 205 and 208 and there is brought about a situation of melting the terminals 205 and 208. Hence, the sub relay 203 is provided other than the main relay 202 to thereby prevent the terminals from being melted by arc discharge.
However, according to the related circuit breaking apparatus 200, there are needed two relays of the main relay 202 and the sub relay 203 and there is needed the control unit 201 for controlling the relays and therefore, there poses a problem that the cost is high and the apparatus is complicated and large-sized.
There is provided an another circuit breaking apparatus of this kind disclosed in Japanese Patent Laid-Open No. 306265/1996 shown in FIG. 27.
As shown by FIG. 27, there is provided a switch mechanism containing chamber 302 at inside of an apparatus main body 301 of the circuit breaking apparatus 300 and the switch mechanism containing chamber 302 is provided with a pair of rod terminals 303 and 304. The pair of rod terminals 303 and 304 are arranged on a straight line at positions separated from each other. Further, the switch mechanism containing chamber 302 is arranged with a connection cylinder portion 305 of a conductive member in a cylindrical shape and elastic contact portions 306 are provided at two locations on an inner peripheral side of the connection cylinder portion 305.
Further, an operating lever member 307 is supported by the connection cylinder portion 305 via a support pin 307a and a lower end of the operating lever member 307 is provided at the apparatus main body 301 rotatably via a rotating shaft 308. An upper end of the operating lever member 307 is exposed to outside from the apparatus main body 301 and a grub portion 309 is provided at the upper end of the exposed operating lever member 307. By operating the operating lever member 307, the connection cylinder portion 305 is moved to slide between a conducting position shown by bold lines in FIG. 27 and a breaking position shown by imaginary lines in FIG. 27.
According to the above-described constitution, the pair of rod terminals 303 and 304 can electrically be connected by disposing the connection cylinder portion 305 at the conducting position by operating the operating lever member 307 and the pair of rod terminals 303 and 304 can electrically be broken by disposing the connection cylinder portion 305 at the breaking position by operating the operating lever member 307. That is, in order to move to slide the connection cylinder portion 305, the operating lever member 307 is connected to the connection cylinder portion 305, a fulcrum of force is constituted by one end side (lower end side) of the operating lever member 307, a force exerting point of the force is constituted by other end side (upper end) of the operating lever member 307 and the connection cylinder portion 305 can be moved by small operating force by utilizing the principle.
However, it is necessary to provide the operating lever member 307 rotatably supported by the connection cylinder portion 305 and move the upper end side of the operating lever 307 (grub portion 309) in parallel with sliding movement of the connection cylinder portion 305 and therefore, there poses a problem that the apparatus is large-sized.
In this case, in order to resolve large-sized formation of the apparatus, there is conceivable a constitution in which a movable plug is provided to be simply able to insert and extract to and from an apparatus main body, a pair of terminals are connected via a conductive portion of the movable plug by inserting the movable plug into the apparatus main body and the pair of terminals are broken by drawing the movable plug from the apparatus main body. However, according to such an apparatus, it is necessary to prevent erroneous insertion by which the movable plug is inserted to the apparatus main body not at a regular rotational position. That is, because according to a constitution in which the movable plug is locked at a circuit closed position, there is a concern of causing inconvenience that the movable plug cannot be locked unless the movable plug is inserted at the regular rotational position, or according to a constitution in which the movable plug is brought into proper contact with the terminal at an inner portion only at a proper rotational position, there is a concern of bringing about various inconveniences of causing contact failure, terminal destruction and the like. Further, according to such an apparatus, when the movable plug is simply inserted into the apparatus main body, large operational force is needed and therefore, a guide groove is provided on the side of the apparatus main body and a projection capable of being inserted into the guide groove is provided at the movable plug, respectively, further, there is provided a guide portion for rotation inclined in a skewed depth direction relative to a direction orthogonal to an inserting direction at a section of the guide groove from a position before finishing to insert the movable plug to a position of finishing to insert the movable plug. Further, it is conceivable that after inserting the movable plug into the apparatus main body to some degree, the movable plug is inserted while rotating the movable plug by operating to rotate the movable plug (convert rotational force into inserting force), thereby, the movable plug is inserted thereinto by small operational force.
However, according to the constitution having the operation of inserting the movable plug and the operation of rotating the movable plug, there is a possibility that an operator misunderstands that the operation has been finished at a time point of finishing the operation of inserting the movable plug and stops operating the operation of the movable plug. Further, when the final operation of rotating the movable plug is not carried out in this way, there poses a problem that there is brought about an incompletely fitted state in which the conductive portion and the terminal cannot firmly be fitted to each other.
There is another related circuit breaking apparatus of this kind disclosed in Japanese Patent Laid-Open No. 144429/1998 shown in FIG. 28 and FIG. 29.
As shown by FIG. 28 and FIG. 29, the circuit breaking apparatus 400 is constituted by an apparatus main body 401 and a movable plug 402 provided attachably and detachably to the apparatus main body 401. The apparatus main body 401 is provided with a pair of female terminals 403 and one of the pair of female terminals 403 is electrically connected to a load portion and other thereof is electrically connected to a power source portion, respectively. A plug insertion hole 404 is formed at a surrounding of the pair of female terminals 403 of the apparatus main body 401 and a pair of guide grooves 405 are formed on left and right sides of an outer periphery of the plug insertion hole 404.
The movable plug 402 is provided with an operating lever 407 provided with a pair of projections 406 at left and right side faces thereof, a plug main body 409 rotatably provided to the operating lever 407 via a rotation support shaft 408 and a pair of male terminals 411 fixed to the plug main body 109 and electrically connected thereto by a bus bar 410.
An operator grubs the operating lever 407, matches the pair of projections 406 to the pair of guide grooves 405 of the apparatus main body 401 and inserts the plug main body 409 into the plug insertion hole 404 of the apparatus main body 401. Then, by a stroke of inserting the movable plug 402, the male terminals 411 are inserted into the female terminals 403 and an interval between the pair of female terminals 403 are electrically connected by the pair of male terminals 411 and the bus bar 410 to thereby bring a power source circuit into a conductive state. Further, the movable plug 402 mounted to the apparatus main body 401 is drawn from the plug insertion hole 404 of the apparatus main body 401. Then, by a stroke of drawing the movable plug 402, the pair of male terminals 411 are detached from the pair of female terminals 403 and the interval between the pair of female terminals 403 is broken to thereby bring the power source circuit into a broken state.
Meanwhile, in the case in which there is a capacitor or the like at the load portion and when the power source circuit is broken by the circuit breaking apparatus 400, a charged state is maintained at the capacitor or the like of the load portion. Therefore, when maintenance or the like is carried out, it is necessary to discharge the capacitor or the like of the load portion, however, the above-described circuit breaking apparatus 400 is not provided with discharging means. Therefore, it is necessary to separately provide discharging means for connecting the load portion to the ground in a circuit broken state and releasing the load portion from the ground in a circuit conducted state at the power source circuit.
Hence, the invention has been carried out in order to resolve the above-described problem and it is an object thereof to provide a circuit breaking apparatus which is small-sized, inexpensive and capable of preventing terminals from being melted by arc discharge without using two relay switches and a control circuit thereof.
Another object of the present invention is to provide a circuit breaking apparatus constituting compact formation of the apparatus and capable of preventing erroneous insertion of a movable plug.
Another object of the present invention is to provide a circuit breaking apparatus capable of discharging a capacitor or the like of a load portion when the circuit breaking apparatus is brought into a circuit broken state from a circuit conducted state.
Another object of the present invention is to provide a circuit breaking apparatus capable of preventing leakage current or the like from being caused by arc discharge of a sacrifice electric pole.
Another object of the present invention is to provide a circuit breaking apparatus capable of making the apparatus compact, achieving a reduction in operational force of a movable plug, further, preventing an incompletely fitted state by incompletely inserting the movable plug from being brought about.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) A circuit breaking apparatus comprising:
a apparatus body;
a load side terminal connected to a load portion and provided in the apparatus body;
a power source side terminal connected to a power source portion and provided in the apparatus body;
a sacrifice electrode portion connected to the power source side terminal and provided in the apparatus body; and
a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the load side terminal to the power source side terminal and a circuit closed position in which the movable plug electrically connects the load side terminal to the power source side terminal,
wherein the load side terminal, the power source side terminal and the sacrifice electrode portion are shifted in a direction of moving the movable plug such that when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode portion and the power source side terminal in order.
(2) The circuit breaking apparatus according to (1), wherein
the sacrifice electrode portion includes a first sacrifice electric pole electrically connected to the power source side terminal through a resister, and a second sacrifice electric pole electrically directly connected to the power source side terminal, and
when the movable plug is moved from the circuit opened position to the circuit closed position, the movable plug is firstly brought into contact with the first sacrifice electric pole and secondly brought into contact with the second sacrifice electric pole.
(3) The circuit breaking apparatus according to (1), wherein the sacrifice electrode portion is electrically directly connected to the power source side terminal.
(4) The circuit breaking apparatus according to (1), wherein a first face of the conductive portion firstly brought into contact with the sacrifice electrode portion and a second face of the conductive portion brought into contact with the power source side terminal, differ from each other.
(5) The circuit breaking apparatus according to (4), wherein
the conductive portion includes a side face which extends along the direction of moving the movable plug and corresponds to the first face and a tapered face on a front end thereof corresponding to the second face.
(6) The circuit breaking apparatus according to (1), wherein the sacrifice electrode portion includes a sacrifice electric pole contactable with the conductive portion and an elastic arm portions connecting the sacrifice electric pole with the power source side terminal.
(7) The circuit breaking apparatus according to (5), wherein
the sacrifice electrode portion includes a sacrifice electric pole contactable with the conductive portion and an elastic arm portions connecting the sacrifice electric pole with the power source side terminal, and
the sacrifice electric pole is elastically slidable on the side face of the conductive portion.
(8) A circuit breaking apparatus comprising:
an apparatus body;
first and second terminals provided in the apparatus body, respectively;
a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the first terminal to the second terminal and a circuit closed position in which the movable plug electrically connects the first terminal to the second terminal,
a guide groove provided at one of the apparatus body and the movable plug; and
a projection insertable into the guide groove and provided at the other of the apparatus body and the movable plug,
wherein the movable plug is inserted into the apparatus body only when the projection is inserted into the guide groove.
(9) The circuit breaking apparatus according to (8), wherein
the first and second terminals have a tubular cylindrical shape, and
the conductive portion is a cylindrical rod insertable into the first and second terminals, respectively, so that the conductive portion is electrically connected with the first and second terminals.
(10) The circuit breaking apparatus according to (9), wherein
the guide groove has a rotation guide portion extending to a depth side in a direction skewed to a direction orthogonal to a direction of inserting the movable plug, and
when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion.
(11) The circuit breaking apparatus according to (10), wherein the movable plug includes an operation lever to which the projection or the guide grooves is provided and which rotatably supports the conductive portion.
(12) The circuit breaking apparatus according to (8), wherein the guide groove includes a projection pickup portion having a large width on a side of an insertion port of the apparatus body firstly inserted with the projection and the width is gradually narrowed toward the insertion depth.
(13) The circuit breaking apparatus according to (8), wherein the guide groove including:
a projection pickup portion including a first end portion having a width three to six times as large as a width of the projection on a side of an insertion port of the apparatus body, and a second end portion having a width slightly wider than the width of the projection, the width of the projection pickup portion being gradually narrowed from the first end portion toward the second end portion;
a straight advancement guide portion having a constant width slightly larger than the width of the projection and extending in an insertion direction of inserting the movable plug, one end thereof being communicated with the second end portion; and
a rotation guide portion extending to a depth side in a direction skewed to a direction orthogonal to the insertion direction, and communicated with the other end of the straight advancement guide.
(14) The circuit breaking apparatus according to (8), wherein the guide groove includes a rotation guide portion extending in a skewed depth direction relative to a direction orthogonal to a direction of inserting the movable plug, and a rotation introducing guide portion having a large radius of curvature in compared with that of the rotation guide portion, and
when the movable plug is moved from the circuit opened position toward the circuit closed position, the projection is moved from a side of the rotation guide portion toward the rotation introducing guide portion.
(15) The circuit breaking apparatus according to (14), wherein
when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion.
(16) The circuit breaking apparatus according to (8), wherein the guide groove includes a rotation guide portion extending in a skewed depth direction relative to a direction orthogonal to a direction of inserting the movable plug, and a rotation introducing guide portion having a large taper angle relative to the direction orthogonal to the direction of inserting the movable plug, and
when the movable plug is moved from the circuit opened position toward the circuit closed position, the projection is moved from a side of the rotation guide portion toward the rotation introducing guide portion.
(17) The circuit breaking apparatus according to (16), wherein
when the conductive portion is in contact with the first and second terminals, the projection is slid along the rotation guide portion.
(18) The circuit breaking apparatus according to (8), wherein the guide groove has a curved shape whose a radius of curvature varies.
(19) A circuit breaking apparatus comprising:
an apparatus body;
a load side terminal connected to a load portion and provided in the apparatus body;
a ground side terminal which is connected to the ground, provided in the apparatus body, and movable between a contact position in which the ground side terminal is in contact with the load side terminal and a separated position in which the ground side terminal is separated from the load side terminal;
a power source side terminal connected to a power source portion and provided in the apparatus body;
a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the conductive portion is not in contact with the power source side terminal and a circuit closed position in which the conductive portion is in contact with the load side terminal and the power source side terminal; and
an urging member for urging the ground side terminal to the contact position,
wherein the ground side terminal is in the contact position when the movable plug is in the circuit opened position, and
wherein the ground side terminal is moved to the separated position against urge force of the urging member in when the movable plug is moved from the circuit opened position to the circuit closed position.
(20) The circuit breaking apparatus according to (19), wherein
the ground side terminal includes a pair of contact portion holders opposed each other with respect to a movement center axis of the movable plug,
in the contact position, the pair of contact portion holders are arranged on a movement locus of the movable plug, and
in the separated position, the pair of contact portion holders are moved in directions separating from each other by a press force of the movable plug and arranged at a position for slidably contact with the conductive portion of the movable plug.
(21) The circuit breaking apparatus according to (19), wherein
the apparatus body is provided with a sacrifice electrode electrically connected to the power source side terminal, and
when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode and the power source side terminal in order.
(22) The circuit breaking apparatus according to (19), wherein the urging member is a spring.
(23) A circuit breaking apparatus comprising:
an apparatus body;
a load side terminal connected to a load portion and provided in the apparatus body;
a power source side terminal connected to a power source portion and provided in the apparatus body;
a sacrifice electrode which is connected to the power source side terminal, provided in the apparatus body and interposed between the load side terminal and the power source side terminal;
a movable plug including a conductive portion and movable with respect to the apparatus body between a circuit opened position in which the movable plug does not electrically connect the load side terminal with the power source side terminal and a circuit closed position in which the movable plug electrically connects the load side terminal with the power source side terminal; and
insulative caps provided at the load side terminal and the power source side terminal, respectively,
wherein when the movable plug is moved from the circuit opened position to the circuit closed position, the conductive portion is brought into contact with the load side terminal, the sacrifice electrode and the power source side terminal in order.
(24) The circuit breaking apparatus according to (23), wherein the insulative cap is provided at one end of the load side terminal facing to the sacrifice electrode.
(25) The circuit breaking apparatus according to (23), wherein the insulative cap is provided at one end of the power source side terminal facing to the sacrifice electrode.
(26) The circuit breaking apparatus according to (23), wherein each of the load side terminal and the power source side terminal includes a cylinder ring portion and a multiple point contact spring member arranged at an inner peripheral face of the cylinder ring portion, and the multiple point contact spring member is fixed to the cylinder ring portion by the insulative cap.